defined for the Zilver PTX stent arm as absence of evidence of binary restenosis or occlusion within the originally treated lesion based on color-flow duplex ultrasound (CFDU) measuring a peak systolic velocity ratio <2.4, and without clinically driven target lesion revascularization (TLR) within 12 months;

defined for the bypass arm as absence of evidence of binary restenosis or occlusion at the proximal and distal anastomoses and over the entire length of the bypass graft, and without clinically driven reintervention to restore flow in the bypass.

For the Zilver PTX stent arm, technical success is defined as the ability to cross and stent the lesion to achieve residual angiographic stenosis no greater than 30% and residual stenosis less than 50% by duplex imaging.

For the bypass arm, technical success is defined as no graft lesion and a low resistance blood flow pattern in the distal graft and outflow artery, as evidenced by duplex.

The objective of this clinical investigation is to evaluate the early and mid-term outcome (after 6 and 12 months) and the long-term (up to 24 months) outcome of the Zilver PTX paclitaxel-eluting stent (Cook) versus bypass surgery for the treatment of TASC C&D femoropopliteal lesions.

Detailed Description

A global noticeable tendency is the increasing prevalence of peripheral artery disease (PAD). Approximately 27 million people in Europe and North America are affected by PAD. Risk factors attaining this high prevalence include age, obesity, nicotine abuse, hypertension, hyperlipidemia, diabetes and family history. PAD can present itself asymptomatically or symptomatically by intermittent claudication (IC) or critical limb ischemia (CLI).

The conservative treatment of PAD comprises of smoking cessation, exercise and management of other risk factors associated with the disease. However, a medical intervention is indicated in those patients presenting with disabling IC, CLI or in cases where conservative treatment does not afford relief.

The Inter-Society Consensus for the Management of PAD (TASC II) published an overview of the different categories of PAD. The TASC II recommendations for the treatment of femoral popliteal lesions are shown in Figure 1. For TASC A & B lesions, the endovascular treatment is preferred and for TASC C & D lesions, the surgical treatment is preferred.

The surgical treatment with prosthetic bypasses yielded good results in numerous trials. Berglund, Björck and Elfström (2005) conducted a retrospective study in which 499 patients were assessed. These patients received an above-knee femoropopliteal bypass with a saphenous vein graft (139 subjects) or an ePTFE graft (360 subjects). Primary patency after 12 months was 87% and 75% for the venous bypass and prosthetic bypass respectively. Jensen et al. (2007) investigated 427 patients in a randomized trial with patients who underwent an above-knee femoropopliteal bypass. Eventually, 205 patients received a PTFE bypass graft and 208 received a Dacron bypass graft (14 patients were excluded). The primary patency rates after 12 months were 70% and 78% for PTFE and Dacron respectively. Kedora et al. (2007) compared 86 patients (100 limbs) with femoropopliteal artery occlusive disease in their randomized trial. 50 limbs were treated with angioplasty and one or more self-expanding stent grafts, the other 50 limbs were treated with a synthetic Dacron or ePTFE bypass graft. After 12 months, the primary patency for the bypass group was 74.2%. In a similar study setup, McQuade, Gable, Hohman, Pearl & Theune (2009) studied 100 limbs in 86 patients with superficial femoral artery occlusive disease. 50 limbs were treated with angioplasty and one or more stent grafts, the other randomized 50 limbs were treated with a synthetic Dacron or ePTFE bypass graft. The bypass arm of this study had a primary patency after 12 months of 77%. A total of 27 patients with TASC D lesions in the superficial femoral artery were analyzed by Hines, Wain, Montecalvo & Feuerman (2010). All patients received a bypass with an endoscopic saphenous vein. After 12 months the primary patency was 73.2%.

At the LINC congress Bosiers (2012) presented an analysis on 100 surgical primary patent bypasses. Surgical primary patency is measured by assessing flow through the bypass. Endovascular primary patency is measured by the absence of binary restenosis (PSV≥2.4), assessed at the proximal and distal anastomoses. A total of 89% of the surgical primary patent bypasses was evaluated as endovascular patent. This analysis shows a margin of approximately 10% which can be taken into account when interpreting the primary patency of surgical bypasses.

Dake et al. (2011) examined 900 lesions in the superficial and popliteal arteries treated with one or more Zilver PTX drug-eluting stents. The mean lesion length was 99.5 (±82.1) mm and the primary patency after 12 months was 86.2%.

Comparison of the surgical bypass with an endovascular approach in femoropopliteal lesions is been a study set-up that has been used many times. To date, a randomized control between bypass and the new drug-eluting technology as not been conducted. The purpose of this trial is to compare the results of a prosthetic bypass treatment with the Zilver PTX drug-eluting stent treatment. Historical data of the primary patency bypass results, taken the 10% difference between surgical and endovascular patencies into account, gives an endovascular primary patency of approximately 70%. In this non-inferiority trial, the proposed primary patency of the Zilver PTX drug-eluting stent is set at 80% to show that the treatment with a drug-eluting stent is comparable to the treatment with a prosthetic bypass.

Patients in the Zilver PTX arm have to be treated by placement of the Zilver PTX drug-eluting stent (Cook), according to standard procedures based on the Instructions for Use. The only pre-treatment allowed prior to placement of the Zilver PTX drug-eluting stent (Cook) is standard PTA. Diameter measurements must be performed of the healthy vessel proximal and distal to the previously stented area. Diameter selection of the Zilver PTX drug-eluting stent (Cook) should result in minimal oversizing. The target lesion needs to be completely covered by using as few stents possible. Post-dilatation can be performed according to the Instructions of Use.

Intervention: Device: Zilver PTX

Active Comparator: prosthetic bypass

Patients in the bypass arm have to be treated with a prosthetic bypass graft according to the institution's standard of care and the Instructions for Use of the prosthetic bypass graft.

Intervention: Device: prosthetic bypass

Publications *

Not Provided

* Includes publications given by the data provider as well as publications
identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.